In early 2024, Kenya, including its capital Nairobi, witnessed an unprecedented surge in temperatures, marking a departure from its typical climate patterns. This phenomenon was identified by the World Meteorological Organization as part of a global trend, citing record-breaking temperatures in 2023. January 2024 emerged as the hottest month on record worldwide. Gilbert Ouma, coordinator of the University of Nairobi’s Institute for Climate Change and Adaptation and an associate professor at the Department of Meteorology, sheds light on some crucial aspects of this occurrence.
What’s unusual about Nairobi’s weather?
Nairobi typically enjoys moderate annual average temperatures, ranging from 24°C to 25°C on the higher end and 17°C to 18°C on the lower end, providing a generally comfortable climate. However, during the December-January-February period, maximum temperatures tend to rise, typically ranging from 26°C to 27°C. This year, temperatures soared in February, reaching between 29°C and 30°C, even spiking to 31°C. This represents an approximately 6°C increase from Nairobi’s usual temperatures, a significant variance that impacts human comfort. While not sustained enough to classify as a heatwave, Nairobi has experienced intermittent waves of hot weather, which individuals can adapt to more easily.
What’s causing the sudden heat?
The prevailing hot weather can be attributed to the northward winds that traverse Kenya from December to February annually. These winds, originating from continental areas, including deserts, intermittently usher in hot weather patterns, as observed recently across East Africa. The trajectory of these winds influences temperatures in Kenya; a straight path over landmasses results in higher temperatures, while a curved path over the Indian Ocean moderates temperatures, bringing cooler weather and rainfall to the region.
Furthermore, the ongoing climate change contributes to rising global temperatures, with record highs documented in the preceding year. Consequently, the relatively high temperatures typical of the December-January-February season may escalate further. Additionally, the abnormal wet conditions in December and January 2024, caused by delayed El Niño rains, temporarily moderated temperatures. However, upon the cessation of rains, customary heat conditions prevailed in February.
The impact of rising temperatures:
Beyond the immediate discomfort caused by hot weather, the broader implications of climate change are profound. Africa has witnessed a steady increase in annual temperatures, accelerating since 1981. This trend extends to changes in extreme weather events, such as storms, which serve as mechanisms for the atmosphere to dissipate excess energy. Consequently, more frequent and intense rainfall events, as well as prolonged droughts, are anticipated.
Ecosystems face disruption, with certain species unable to adapt to the shifting climate. For instance, mosquitoes struggle to survive outside temperature ranges of 17°C to 35°C. Consequently, regions experiencing temperature shifts outside this range may encounter new health challenges, such as malaria outbreaks. Long-term health effects on human populations include heat-related illnesses, kidney disease, hypertension, cardiovascular issues, and respiratory ailments like asthma. Addressing these challenges necessitates concerted efforts to mitigate climate change and adapt to its consequences.
